Electric vehicles generally relate to vehicles that have batteries or battery units that store energy, where the batteries are designed to provide electrical power for propelling and accelerating the vehicle and also for providing power to electrical systems used in the vehicle. The stored energy is consumed when the electric vehicle is used and the battery needs to be re-charged in order to replenish the level of stored energy through a connection to an external electric power supply.
Hybrid electric vehicles are using a combination of an internal combustion engine system and an electric propulsion system. The internal combustion engine can be operated intermittently to provide power to the hybrid electric vehicle's driveline when needed depending on the driving conditions. In low speed driving situations the vehicle may be operated by only using the electric propulsion system and when more power is needed the internal combustion engine supplies additional power to the driveline, for example when driving at higher speeds. Also hybrid electric vehicles have batteries or battery units that store energy, where the batteries are used for providing electrical power for propelling and accelerating the vehicle and for systems used in the vehicle. A plug-in hybrid electric vehicle uses a system with re-chargeable batteries that can be restored into a full charge condition through a connection to an external electric power supply.
When re-charging batteries in electric vehicles or hybrid electric vehicles an on-board charging system is generally used. The onboard charger often uses a rectifier circuit to transform alternating current (AC) from the external electric power supply, such as an electrical grid, to direct current (DC) suitable for re-charging the batteries. The on-board charger may be connected to the electrical grid via a charging cable having a charging plug that is designed to match a corresponding charging socket arranged in the vehicle.
One common problem with this type of battery re-charging is that cost and thermal issues limit how much power the rectifier can handle. It is therefore sometimes better to use an external charging station that delivers direct current (DC) to the vehicle's batteries for a much faster re-charging, instead of using the onboard charging system. Dedicated external charging stations for fast vehicle battery re-charging operations can be built in permanent locations and provided with high-current connections to the electrical grid. Also these fast charging stations use charging cables for connecting the charging station to the vehicles. The charging cables have a direct current charging plug that is designed to match a corresponding direct current charging socket arranged in the vehicle.
There are on the market today different direct current charging systems that are used for efficient and fast charging of batteries in electric and hybrid electric vehicles. Examples of such charging systems used today are CHAdeMO (Charge de Move), CCS (Combined Charging System) and Tesla Superchargers, where each system has its own unique type of charging plug and socket configuration, giving each system its own type of charging interface.
This setup with different direct current charging systems adds complexity to the construction of the battery units of electric vehicles and hybrid electric vehicles if more than one system for direct current re-charging should be possible to use in the vehicle, since the vehicle has to be equipped with more than one type of charging interface connected to the battery unit. The battery unit then has to be equipped with more than one set of components for the different charging interfaces, such as separate contactors and control units for each type of charging system to avoid that more than one direct current charging system is connected to the vehicle, and to avoid that a voltage is present on the non-used connectors when charging. If for example a vehicle is designed for re-charging with all three direct current charging systems mentioned above, the vehicle must be equipped with one CHAdeMO connecting unit, one CCS connecting unit and one Tesla Supercharger connecting unit, where each unit needs its separate components in the battery unit.
There are many disadvantages with such a battery unit construction, e.g. since there are space and weight limitations when constructing the vehicle. The size of the battery units should be as small as possible and the need for extra components in the battery units adds unwanted volume and weight. Another possibility would be to use separate charging adapters for use with different type of chargers, but then you may need to carry a number of different adapters on board the vehicle.
There is thus a need for an improved construction where different charging systems can be used in a vehicle, without increasing volume, weight, and complexity to the battery units with many different components.